The invention is in respect of a roller mill with a liquid-gas, that is to say hydropneumatic, suspension system weighting the rollers, in the case of which the driving system for the grinding pan is placed under the pan. The rollers running on the grinding pan are stationarily placed, each of them being bearinged on a turnpin in a rocking lever, which is able to be rocked about an axis at its lower end so that the weighted rollers may be moved in an upright direction on running over the face of the grinding pan. The top ends of the rocking levers are joined together by a spring or suspension system, by which the grinding rollers are made to be responsible for a springing force or pressure acting on the grinding pan. In the past designs have been based on two different teachings with respect to the spring system. In the first teaching the springing effect is produced by a torsion pipe running in the cross-direction through the mill housing. In the case of the second teaching use was made of two torsion pipes which, in the case of a T-like design of the rocking lever were run out to a position on the outside of the mill housing.
Such spring systems may no longer be used with the current, ever increasing mill sizes, because the rolling forces become greater and mechanical spring designs take up overgreat amounts of space.
For meeting the needs of greater mill sizes liquid-gas roller suspension systems have been designed. More specially in the case of a liquid-gas roller suspension system there is, however, the shortcoming that the great mass of the cylinder has to be placed between the rocking levers for the purpose of having enough space for the liquid-gas connection system. On upward and downward motion of the grinding rollers, when grinding operations are taking place, the cylinders are necessarily acted upon by cross-vibrations, which are likely to be the cause of resonant vibrations and mechanical fatigue.